FileTransform error feedback and web.config

[aarondel4]

This file spits out the same error for several different scenarios/code paths:

azure-pipelines-tasks-common-packages/common-npm-packages/webdeployment-common/fileTransformationsUtility.ts

Line 84 in d4d4458

if(isTransformationApplied) {

Everywhere isTransformationApplied is used to signal different scenarios with a single message.

Trying to run a FileTransform during the beginning of a deployment pipeline to apply transforms but I get this error.

Task:

- task: FileTransform@2
  inputs:
    folderPath: '$(Pipeline.Workspace)/drop/$(Build.BuildId)/${{ parameters.appProjectName }}.zip'
    enableXmlTransform: true
    xmlTransformationRules: |
      -transform **/Web.abc-dev.config -xml **/Web.config  

Transform(verified by downloading ADO build artifact that is input to pipeline):

<?xml version="1.0" encoding="utf-8"?>
<configuration xmlns:xdt="http://schemas.microsoft.com/XML-Document-Transform">
  <system.web>
    <compilation debug="false" xdt:Transform="SetAttributes" />
  </system.web>
</configuration>

Web.config snippet(verified in build artifact):

<system.web>
	<compilation debug="true" targetFramework="4.8">
		<assemblies>
			<add assembly="System.Runtime, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"/>
		</assemblies>
	</compilation>
</system.web>

Snippet Debug Log:

##[debug]  C:\a\_temp\temp_web_package_4513814385960955\Content\D_C\a\1\s\src\ABCProject\obj\Release\Package\PackageTmp\Web.config (file)
##[debug]  C:\a\_temp\temp_web_package_4513814385960955\Content\D_C\a\1\s\src\ABCProject\obj\Release\Package\PackageTmp\Web.efs-dev.config (file)
...
##[debug]  C:\a\_temp\temp_web_package_4513814385960955\parameters.xml (file)
##[debug]  C:\a\_temp\temp_web_package_4513814385960955\systemInfo.xml (file)
##[debug]2093 results
##[debug]found 2093 paths
##[debug]applying include pattern
##[debug]adjustedPattern: 'C:\a\_temp\temp_web_package_4513814385960955\**/Web.config'
##[debug]12 matches
##[debug]12 final results
##[warning]Unable to apply transformation for the given package - Changes are already present in the package.

Can see the files exist, and that the debug attribute is different, but the transform says changes are already present.

[aarondel4]

After reviewing source code for specialXdtTransformation(), I determined that in this particular case, the problem was that I was using forward slashes rather than double backslashes in the transform options:

    xmlTransformationRules: |
      -transform **\\Web.abc-dev.config -xml **\\Web.config  

So the error message was misleading. It implied matching source and transformation files were found, but the effect of the transformation was that no change occurred. This led me to focus on the xdt in the transform file and trying to determine why its changes weren't being applied. Rather, in actuality no matching files were found by specialXdtTransformation() due to the formatting of the path patterns in the -transform/-xml options.